what percentage of fat/glycogen is burned each day

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what percentage of fat/glycogen is burned each day

Postby wkriski » Tue Dec 17, 2013 6:01 am

I know you've discussed exercise and fat loss before but I was wondering if you knew what percentage of fat people burn during the day if they are relatively sedentary. Is it all carbs or do they burn some fat?

So say someone has some excess fat and they require 2500 calories a day to maintain. If they ate very low fat would they still lose fat because each day the body would use some of the fat stores and some of the carbs that were eaten, or would the body just use carbs and only use fat once the glycogen stores are depleted?
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Re: what percentage of fat/glycogen is burned each day

Postby Lani Muelrath » Tue Dec 24, 2013 4:42 pm

wkriski wrote:I know you've discussed exercise and fat loss before but I was wondering if you knew what percentage of fat people burn during the day if they are relatively sedentary. Is it all carbs or do they burn some fat?

So say someone has some excess fat and they require 2500 calories a day to maintain. If they ate very low fat would they still lose fat because each day the body would use some of the fat stores and some of the carbs that were eaten, or would the body just use carbs and only use fat once the glycogen stores are depleted?


HI wkriski!

The body is always burning a mix of fuels. When intensity steps up as it is during hard exercise, a greater percentage of fuel comes from glycogen stores as it is more readily available to the body. At lower intensities of exercise, the percentage of fuel from glycogen stores can drop a little and fuel from fat stores picks up. This is because there is time for the body to get oxygen to metabolize fat. So anaerobic exercise relies more heavily on glycogen stores, and the inverse is true for aerobic exercise.

It does lead me to wonder why you ask the question, however, so I can be most helpful. Many times people are looking for a way to 'burn the most fat' when they exercise and adjust intensity accordingly for weight loss. Bottom line is to get some calorie burning going on - it's the calorie deficit you are looking for in that case. If training for long distance competition, you may want to look at your training differently in light of fuel source.

Hope this helps!
Lani
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Re: what percentage of fat/glycogen is burned each day

Postby wkriski » Fri Mar 28, 2014 8:02 am

Just looking for the optimal time to do cardio for fat burning as some people are saying to do it first thing in the morning after carbs stores are low. I actually found your article on this and agree that it's not really worth exercising first thing in the morning.

I've lost 27+ lbs of fat and am getting lean but some experts talk about time of day between eating and exercising. But if we burn 50/50 at rest in general then it wouldn't really matter and overall calorie deficit would be more important. I tend to be in that camp.
Last edited by wkriski on Sat Mar 29, 2014 6:58 am, edited 1 time in total.
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Re: what percentage of fat/glycogen is burned each day

Postby Lani Muelrath » Sat Mar 29, 2014 6:50 am

wkriski wrote:Just looking for the optimal time to do cardio for fat burning as some people are saying to do it first thing in the morning after carbs stores are low. I actually found your article on this and agree that it's not really worth exercising first thing in the morning.

I've lost 27+ lbs of fat and am getting lean but some experts talk about time of day between eating and exercising. But if we burn 50/50 then it wouldn't really matter and overall calorie deficit would be more important. I tend to be in that camp.


Wkriski,

I'm not convinced that fretting over the perfect window for 'burning fat' is worth it. Better to simply get the exercise in. We don't burn '50/50', it's a sliding scale mix depending on a whole lot of elements - glycogen stores, recent intake, hours fasting. Congrats on the fat loss, by the way!
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Re: what percentage of fat/glycogen is burned each day

Postby wkriski » Sat Mar 29, 2014 3:56 pm

Totally agree, some of the reasons I ask is that Robert Cheeke, vegan bodybuilder just did a video on his upcoming book and he talks about exercising in the morning to burn fat. I also read this a while back in Body for Life and a lot of people believe this.. Since I now have a Youtube channel and Facebook page I get a lot of questions so I'm trying to help people with facts and common sense. Also I just took an online nutrition course from Vanderbilt University with a guest professor who trains Olympic athletes and he believes in the time of day concept with eating and exercising, not based on entire day. I like the keep it simple and consistent approach. Do you have any scientific references for time of day exercising not really mattering for fat burning that I can reference?
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Re: what percentage of fat/glycogen is burned each day

Postby Lani Muelrath » Sat Mar 29, 2014 4:49 pm

wkriski wrote:Totally agree, some of the reasons I ask is that Robert Cheeke, vegan bodybuilder just did a video on his upcoming book and he talks about exercising in the morning to burn fat. I also read this a while back in Body for Life and a lot of people believe this.. Since I now have a Youtube channel and Facebook page I get a lot of questions so I'm trying to help people with facts and common sense. Also I just took an online nutrition course from Vanderbilt University with a guest professor who trains Olympic athletes and he believes in the time of day concept with eating and exercising, not based on entire day. I like the keep it simple and consistent approach. Do you have any scientific references for time of day exercising not really mattering for fat burning that I can reference?


Wkriski,

I'm the first person to say if there's new evidence, show it to me and we'll consider it. More often than not, this kind of information simply distracts people from getting in the physical activity they need. High level athlete coaches are constantly tweaking their client's regimes for this or that, but does that make it necessary for us to follow suit? And how much 'fat burning' are we talking about with this approach anyway. In a year's time, will we see a 20 lb difference - or a 2 lbs difference - or none at all? If running on empty makes us a little less energetic, and we don't work as hard, have we accomplished what we want to?

Here's an article you might enjoy:

http://www.unm.edu/~lkravitz/Article%20 ... 09UNM.html

Lani
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